1. Field of the Invention
The present invention relates to a method and an apparatus for sampling a synchronous pattern, and particularly to a method and an apparatus for exactly sampling a synchronous pattern from data including an error.
2. Description of the Prior Art
Generally, in order to read data recorded in digital data form from a video tape for a video cassette recorder (VCR) or a digital-video home system (D-VHS) and reproduce an original image, an accurate judging of each data region from the read data and a logical operation appropriate to the judged data region should be carried out. Presently, the judging of the data region is accomplished by sampling a synchronous pattern concerning each data region from the read data of the video tape. However, in the read data from the video tape, an error component due to the frequent generation of a bit impact, a bit insertion, a bit deletion, etc. is included because of a defect of the video tape or an external factor. Also, there is a probability that the read data may include the same data as the synchronous pattern. Accordingly, the exact sampling of the synchronous pattern from the read data of the video tape is difficult.
U.S. Pat. No. 4,674,088 (issued to Wayne D. Grover) discloses an example of a method for sampling a synchronous pattern. In this patent, a method for sampling synchronization with frames of a serial data stream including a predetermined frame pattern is disclosed.